First question: Should I max cold mastery? I have +19 in skills so I'm around -125 cold resists so far. I will use Freesh to PvM rush at times and for PvP mainly.

Second question: Is 2400 mana with BO good for PvP? I have 665 life so far and was wondering if I should invest some into vitality.

Third question: Would you keep CoH over Arkaines armor (Zharous really advocates Arkaines for life boost) for PvP?

Last question: I know Nightwing/Death's Fathom will add more damage, but any other gear suggestion for PvM? My current gear hits the 75 fcr and 86 fhr breakpoints so far. I have a Wizspike (great mana and fcr boost) and Whistan's shield (great block) in stash.

Arkaines has such an ugly str req. I prefer going enigma or coh. Enigma because it saves you alot of str to equip spirit. (More energy/vital)

Please hit 105 FCR as priority with the use of nightwings/fanthom.

Spirit shield 35
Arach 20
Fanthom 20
Magefist 20
Either 3cold skill/10fcr amulet or 2 sorc/10fcr/mods rare amulet. Instead of this, you can get a 10fcr ring but getting fcr on the amulet will save you a skill (soj)

This should hit 105fcr.

I'd consider orb to be the kind of build where you need certain items for it to work in pvp. If you cannot attain these items nor hit the wanted bp and decent life:mana then I would consider just going full vital blizzard, lightning, or fire.

Do trade away the cta pb for a cta lower req sword. You'll be investing unnecessary stats into dext just to use it.

I use Firewall to deal with cold immunes, and it was funny trying to complete the Den of Evil quest with FW. Is there another option to deal with cold immunes, since cold mastery can't break cold immunes?

I don't want to switch out my Maras for a 10 FCR ammy. Would a Fort switch for CoH be wise to get the necessary FCR (105 bp), or would Skin of the Viper be best? Thanks for the suggestion to use Nightwings and Fathom. I like the Shako/HotO combo because of the resist, life, and mana they provide, but I understand the need for damage in PvP.

I went for max block with Whistans, and I could even switch with a Stormshield. Should I remake to place in vitality instead?

Frozen Orb is kinda easy to absorb in PvP so if you are pubing, or dueling where ppl might use dual Ravens + Snowclash (+ stacked res) you will really need the boost in dmg from fathom+NW.

Fort can't give you much that either a Vipermagi or a CoH can't give. Fort has no skills, has less res than a vipermagi and lots of less res than CoH. If you need FCR vipermagi give more than Fort. Fort gives somewhere around 90-140 (right?) life, that can't be boosted by BO. Fort will pretty much only give you more defence than the other two armours can, and a +5% max light res. Even though it's usefull it's not worth your armour slot.. I'd go with the gear DayDream suggested..